You don't need to head to the gym or buy exercise equipment when you can get a great workout with just your body. If you happen to be taking your kids to the playground or just want to take your workout outdoors, the playground makes for a excellent, free gym.

(Note: As Art of Manliness cautions, if you don't have kids accompanying you and you're a guy, it's best to head to the playground when no kids are there, lest you look like you're there for the wrong reasons.)